Internal combustion engines combust an air/fuel mixture within cylinders to drive pistons that rotatably turn a crankshaft to generate drive torque. Direct injection (DI) engines have fuel systems that inject fuel directly into the cylinders via respective fuel injectors. The fuel is typically highly pressurized in a fuel rail that supplies the fuel to the fuel injectors. A DI fuel pump supplies the fuel to the fuel rail until a fuel pressure in the fuel rail reaches the desired high pressure. The DI fuel pump has a full stroke that corresponds to a maximum amount of fuel able to be supplied by the DI fuel pump. During certain engine operating conditions, however, a full stroke of the DI fuel pump is not necessary, which results in pumping losses if not accounted for. Thus, while such DI fuel systems work for their intended purpose, there remains a need for improvement in the relevant art.